This proposal represents a request to support participation in the Pediatric Oncology Group (POG). This cooperative research is devoted to the investigation of chemotherapeutic approaches to acute leukemia and other neoplastic diseases of childhood. Significant palliation and prolongation of survival has been achieved and contributions have been made in clinical pharmacology. However, the real objective of these studies is the eradication of neoplastic diseases by treatment. Studies are being designed to reflect an increasing intensity of attack on the neoplastic cell. The cooperative group technique permits prompt evaluation in series of reasonable size of promising leads in chemotherapy. These leads or new approaches are often suggested by the results of the group's own work in clinical oncology. Thus, a completed protocol often suggests the new avenues to be explored in new protocols. In addition, protocols are designed to exploit maximal clinical or conceptual advances made in experimental animals and/or clinical pilot studies. The Division of Pediatric Hematology-Oncology in the Department of Pediatrics at the University of California, San Diego (UCSD) has a 10 year involvement in cooperative group studies with Cancer and Leukemia Group B prior to joining forces with the Pediatric Oncology Group in 1980. Between January 1, 1983 and December 31, 1984, we have had 129 patient registrations on 26 group protocol studies. In addition, the P.I. coordinated a Phase II study o n VP-16-213 and completed a draft on a Group Protocol study on the treatment of early stage Hodgkin's disease, and other UCSD investigators served as coordinators for Group Protocols on germ cell tumors, bone marrow transplantation for patients with ALL in second remission or involved in the laboratory investigation of Group Protocol studies in T-cell ALL or neuroblastoma. We plan to continue our active participation in all phases of POG activities.